Finding Trees in a Crown Height Model

[MohammadDashti1]

Hi,

I have a Crown Height Model of trees created from lidar points. I am trying to delineate and count trees.

I tried to use watershed delineation to delinerate tree canopy, but many trees were missed and other were mixed into one watershed.


the other method I want to use but I cannot find the tools for it is finding local minimum to delineate the trees.
then find local maximum to fine the tree tops.

Can you help with how can I improve the inverse watershed delineation, and hoe to find local maxima and local minima?

Thanks a lot,
Mohammad Dashti

[JeffreyEvans]

Some papers/methods that you should be aware of:

Wavelets:
Falkowski, M.J., A.M.S. Smith, A.T. Hudak, P.E. Gessler, L.A. Vierling & N.L. Crookston (2006). Automated estimation of individual conifer tree height and crown diameter via Two-dimensional spatial wavelet analysis of lidar data, Canadian Journal of Remote Sensing, 32(1):153-161.

Falkowski, M.J., A.M.S. Smith, P.E. Gessler, A.T. Hudak, L.A. Vierling & J.S. Evans. (2008). The influence of conifer forest canopy cover on the accuracy of two individual tree measurement algorithms using lidar data. Canadian Journal of Remote Sensing 34(2):338-350.

You can contact the corresponding author (at Michigan Tech now) for the wavelet code.

Variable-window filtering:
Popescu, S.C., R.H. Wynne, R.F. Nelson (2002) Estimating plot-level tree heights with lidar: local filtering with a canopy-height based variable window size. Computers and Electronics in Agriculture 37:71-95

Here is the URL for downloading the TreeVaW software.
http://www-ssl.tamu.edu/personnel/s_popescu/TreeVaW/

[MohammadDashti1]

Thanks for your help
I will read and try these methods

[vasanthreddy]

Try Canopy Maxima utility from "Fusion LiDAR"
http://forsys.cfr.washington.edu/fusion/fusionlatest.html